This glossary contains nearly 300 words & terms associated with drug rehab and alcohol addiction treatment. Many of these are the confusing technical terms you may hear or read from health professionals or law enforcement personnel.

For complete information about specific drugs, including usage methods and statistics, side effects, photos and pictures, discussions of addiction treatment modalities, and some common drug street names, follow the Related Links at the right side of this page.

A

Absorption The process the body uses to move elements from the outside world into the blood and other tissues. Food is absorbed through the stomach and intestines. Nicotine is absorbed through the lungs.

Abstinence The conscious choice not to use drugs. The term "abstinence" usually refers to the decision to end the use of a drug as part of the process of recovery from addiction.

Acetaldehyde The metabolite that results when alcohol dehydrogenase breaks down alcohol in the body.

Acetylcholine A neurotransmitter. Acetylcholine is used by spinal cord neurons to control muscles and by many other neurons in the brain as well. Nicotine binds to one type of acetylcholine receptor.

Action potential The electrical part of a neuron's two-part, electrical-chemical message. An action potential consists of a brief pulse of electrical current that travels along the axon to relay messages over long distances.

Acute effects The short-term effects of a drug. Acute effects are those that people feel shortly after they ingest a drug and are under its influence (e.g., while they are intoxicated).

Adaptive behaviors Useful behaviors we acquire as we respond to the world around us. Adaptive behaviors help us get the things we want and need for life.

Addiction A chronic, relapsing disease, characterized by compulsive (loss of control) of drug-seeking and drug-taking despite adverse health, social, or legal consequences to continued use, and by neurochemical and molecular changes in the brain. Also often characterized by relapses during recovery.

Addictive drugs Drugs that change the brain, change behavior, and lead to the loss of control of drug-taking behavior.

Adenosine A neurotransmitter that binds to the adenosine receptor. Caffeine is an adenosine antagonist and prevents adenosine from binding with its receptor.

Adrenal gland A small gland in the body that releases a variety of hormones that help us deal with stress. Two of these hormones, epinephrine and norepinephrine, are also part of the flight-or-fight response. Cocaine sharply increases the levels of these hormones in the body.

Agonist A chemically simple, but psychoactively complex drug commonly used in many beverages. Alcohol is a depressant drug with significant liability for abuse and addiction.

Alcohol addiction or alcoholism or Alcohol dependence A condition that includes alcohol craving and continued dependence on alcohol, repeated excessive use of alcoholic beverages, drinking alcohol despite repeated alcohol-related problems, such as losing a job or getting into trouble with the law or the breakup of one's family. Symptoms include craving alcohol, impaired control, physical alcohol dependence, and increased alcohol tolerance.

Alcohol dehydrogenase The enzyme found mainly in the liver and stomach that breaks down (metabolizes) alcohol.

Alcoholics Anonymous One of the earliest forms of addiction treatment in the United States, AA developed the 12-step approach to assisting recovery from alcohol addiction (alcoholism). Several other anonymous groups have adapted the 12-step approach to help people recover from addiction to other drugs (e.g., Narcotics Anonymous, Cocaine Anonymous, Pot Smokers Anonymous.

Alveoli Tiny, balloon-like air sacks in the lungs. Alveoli are designed to allow oxygen to pass rapidly into the blood and are also efficient at absorbing inhaled drugs.

Alzheimer's disease A degenerative disease in which neurons of the brain die, leading to the loss of the ability to think, learn and remember (dementia).

Amino acids Small chemical compounds that are the building blocks of proteins.

Amphetamines Stimulant drugs whose effects are very similar to cocaine.

Analgesics Drugs that relieve pain.

Analog A drug whose chemical structure has been slightly modified from a parent compound but which has similar effects. There are many analogs to morphine or to LSD. See Designer drug.

Anandamide The endogenous neurotransmitter that binds to the cannabinoid receptor.

Anesthesia The loss of sensation, primarily to pain, often accompanied by the loss of consciousness.

Antagonist A chemical that binds to a receptor and blocks it, producing no response, and preventing agonists from binding, or attaching, to the receptor. Antagonists include caffeine and naloxone.

Assessment The diagnostic process in which a professional examines a drug user to determine the extent of the person's drug use, whether he or she is addicted, and what type of treatment might be most effective.

Auditory cortex That part of the cerebral cortex that processes sounds and produces our awareness of them.

Axon The cable-like structure neurons used to send messages to other neurons. It carries the neuron's electrical message.

Axon terminal The structure at the end of an axon that produces and releases chemicals (neurotransmitters) to transmit the neuron's message across the synapse to another neuron.

Barbiturates Depressant drugs that produce relaxation and sleep. Barbiturates include sleeping pills such as pentobarbital (Nembutal) and secobarbital (Seconal).

Basal ganglia The large, complex set of brain structures involved in generating movements, in some cognitive functions, and in some emotional and motivational activities. The basal ganglia and the cerebral cortex work together to refine movements, thoughts, and feelings.

Behavior The observable activity of humans and animals.

Behaviorism The study of behavior, especially using operant conditioning.

Benzodiazepines The so-called "minor" tranquilizers, CNS depressants prescribed to relieve anxiety and produce sleep. Benzodiazepines include tranquilizers such as diazepam (Valium) and alprazolam (Xanax) and sleeping pills such as flurazepam (Dalmane) and triazolam (Halcion).

Bernard, Claude The physiologist who coined the term "homeostasis."

Bind What occurs when a neurotransmitter attaches itself to a receptor. The neurotransmitter is said to "bind" to the receptor.

Binge Uninterrupted consumption of a drug for several hours or days.

Bolus A concentrated amount of drug; a dose injected rapidly into a vein, a rounded mass of matter.

Brain That part of the central nervous system inside our heads. Our brain is the seat of all our perceptions, thoughts, feelings and voluntary movements.

Brain reward system A brain circuit that, when activated, reinforces behaviors. The circuit includes the dopamine-containing neurons of the ventral tegmental area, the nucleus accumbens, and part of the prefrontal cortex. We perceive the activation of this circuit as pleasure.

Brain stem The relatively primitive brain structure that starts where our spinal cord enters our head. Neurons within the brain stem control basic functions such as heart rate and breathing.

Broca, Paul The scientist who identified the area in the brain responsible for producing speech, now called Broca's area.

Buprenorphine A long-lasting opiate analgesic that has both opiate agonist and antagonist properties. Buprenorphine shows promise for treating heroin addiction.

Cannabinoid receptor The receptor in the brain that recognizes THC, the active ingredient in marijuana. Marijuana exerts its psychoactive effects via this receptor.

Cannabis The botanical name for the plant from which marijuana comes.

Capillaries The smallest blood vessels. Oxygen and nutrients leave the bloodstream through capillaries to get into the body. Gases from the alveoli enter the bloodstream through capillaries in the lungs.

Cell body The central structure of a neuron, which contains all of the molecular parts that keep the cell alive, generate new parts, and repair or destroy existing parts.

Cell membrane The outside covering, or "skin" or a cell. Receptors and ion channels are embedded in it.

Cellular metabolism The production of energy and new materials in a cell.

Central nervous system The brain and spinal cord.

Cerebral cortex The large, deeply folded outer layers of the brain that make our heads so big. The cortex carries out complex perceptual, cognitive, and motor tasks.

"China white" A designer drug" that was an opiate derivative. Some batches contained a neurotoxin called MPTP, which killed neurons that make dopamine, producing symptoms similar to Parkinson's disease.

Cholinergic The adjective derived from acetylcholine. A neuron that contains acetylcholine is a cholinergic neuron.

Circuits A group of cortical fields or nuclei that are linked together by their axons to perform a specific brain function. Core components or circuits are constantly in touch with each other, whereas other components can be brought in as the need arises.

Classical conditioning The form of implicit, unconscious learning in which a neutral stimulus becomes associated with a significant stimulus through repeated pairing of the two.

CNS Central Nervous System -- the brain and spinal cord.

CNS depressants A class of drugs that slow CNS function, some of which are used to treat anxiety and sleeping disorders; includes barbiturates and benzodiazepines.

Cocaine A highly addictive stimulant drug derived from the cocoa plant that produces profound feelings of pleasure. See Crack.

Codeine A natural opioid compound that is a relatively weak, but still effective, opiate analgesic. It has also been used to treat other problems (e.g., to relieve coughing).

Cognitive functions Higher brain functions involving the manipulation of information from the senses and from memory. They often require awareness and judgment, and they enable us to know and to analyze problems and plan solutions -- in short, to think.

Consciousness Our own awareness of ourselves and the world; the mental processes that we can perceive; our thoughts and feelings.

Cortical field A large aggregation of millions of nerve cells in a circumscribed region of the cerebral cortex, which together carry out a specific function, receive connections from the same places, and have a common structural arrangement. There are many dozens of such fields in the cerebral cortex. Elsewhere in the brain such groups are called nuclei.

Crack A chemically altered form of cocaine that is smoked.

Craving Hunger for drugs. It is caused by drug-induced changes that occur in the brain with the development of addiction and arises from a need of the brain to maintain a state of homeostasis that includes the presence of the drug.

Cues Formerly neutral stimuli that acquire the ability to elicit drug-craving through classical condition. Cues are also called triggers.

Detoxification The process of removing a drug from the body. This is the initial period addicts must go through to become drug-free. Withdrawal symptoms appear early during this process. Depending on the drug, detoxification lasts for a few days to a week or more.

Dopamine The neurotransmitter that produces feelings of pleasure when released by the brain reward system.

Dopamine transporter A structure that straddles the cell membranes of axon terminals of dopamine-releasing neurons and rapidly removes dopamine from the synapse.

Double-blind trials Studies of an experimental drug in which neither patient nor doctor knows whether the patient is receiving the experimental drug or some alternative (which might be a placebo if no treatment already exists).

Dronabinol The generic name of synthetic THC.

Drug abuse Using illegal drugs; using legal drugs inappropriately. The repeated, high-dose, self-administration of drugs to produce pleasure, to alleviate stress, or to alter or avoid reality (or all three).

Drug addiction See Addiction.

Drug-free treatment A approach to helping addicts recover from addiction without the use of medication.

Drug treatment A combination of detoxification, psychosocial therapy and, if required, skill acquisition to help people recover from addiction.

Drug rehab An umbrella term for a variety of processes by which a person addicted to a drug stops using that drug and is rehabilitated (rehab=rehabilitation) from drug or alcohol dependence.

Dynorphins Peptides with opiate-like effects that are made by neurons and used as neurotransmitters; one of the endogenous opiods that binds to opiate receptors.

Habilitate The process of teaching the skills needed for successful living. Habilitation helps people recover from addiction by teaching life skills that were never learned because drug use interfered with the learning and maturation process. Habilitation is especially important for addicts who started drug use young.

Halcion A depressant drug of the benzodiazepine family used to induce sleep.

Hallucinogens A diverse group of drugs that alter perceptions, thoughts and feelings. Hallucinogens do not produce hallucinations. These drugs include LSD, mescaline, MDMA (ecstasy), PCP, and psilocybin (magic mushrooms).

Heroin The potent, widely abused opiate that produces a profound addiction. It consists of two morphine molecules linked together chemically.

Hippocampus A brain structure that is involved in emotions, motivation, and learning. It plays an important role for short-term (working) memory and is crucial for our ability to form long-term memories.

Homeostasis The process of keeping the internal environment of the body stable while the outside world changes.

Hypothalamus The part of the brain that controls many bodily functions, including feeding, drinking, and the release of many hormones.

Implicit memory The memories acquired through unconscious learning processes, such as operant and classical conditioning.

Inhalants Any drug administered by breathing in its vapors. Most inhalants are organic solvents such as glue and paint thinner, or anesthetic gases such as ether and nitrous oxide.

Inhibitory neurotransmitter A neurotransmitter that acts to prevent a neuron from firing an action potential.

Inpatient treatment Residential treatment for drug addiction in a hospital or clinic.

Interneuron Any neuron that only sends its messages locally (within a millimeter or so). Many are inhibitory.

Intervention The act of interrupting addiction and persuading the addict to enter treatment.

Intervention counselor A person who conducts an intervention with an addict and the addict's family and close friends.

Intoxication Being under the influence of, and responding to, the acute effects of a psychoactive drug. Intoxication typically includes feelings of pleasure, altered emotional responsiveness, altered perception, and impaired judgment and performance.

Kinesthetic information Information from our muscles and joints that tells us where our body is in space and how its various parts are oriented in relation to each other. Kinesthetic information is crucial for making accurate movements.

Naloxone A short-acting opiate antagonist that binds to opiate receptors and blocks them, preventing opiates from binding to these receptors. Naloxone is used to treat opiate overdoses.

Naltrexone A long-lasting opiate antagonist used for the treatment of heroin addiction, and more recently used for the treatment of alcohol addiction.

Narcolepsy A disorder characterized by uncontrollable episodes of deep sleep.

Negative reinforcement Reward generated by the removal of painful or stressful conditions or events.

Nembutal (pentobarbital) A depressant drug of the barbiturate family used to induce sleep.

Neural substrate The set of brain structures that underlies specific behaviors or psychological states.

Neurochemicals Neurotransmitters and other brain chemicals produced by neurons.

Neuron Nerve cell. Neurons are unique cells found in the brain and body that are specialized to process and transmit information.

Neuroscience The study of how the brain and nervous system work. Neuroscience integrates more traditional scientific approaches such as anatomy, physiology, and biochemistry, along with newer fields such as molecular biology and computer science, to understand how the nervous system functions.

Neurotoxins Substances that damage or kill neurons.

Neurotransmission The process that occurs when a neuron releases neurotransmitters to communicate with another neuron across the synapse.

Neurotransmitter Chemicals produced by neurons to carry their messages to other neurons.

Nicotine The drug in tobacco that is addictive. Nicotine also activates a specific kind of acetylcholine receptor.

Nicotine gum, nicotine patch Two methods of delivering small amounts of nicotine into the bodies of people who are addicted to nicotine to help them quit smoking cigarettes by preventing nicotine withdrawal.

Nicotinic cholinergic receptor One of two acetylcholine receptors. This one responds to nicotine as well as acetylcholine.

Nitrous oxide An inhalant, also known as "laughing gas." Nitrous oxide is a weak anesthetic that does not produce unconsciousness.

Norepinephrine A neurotransmitter and a hormone. It is released by the sympathetic nervous system onto the heart, blood vessels, and other organs and by the adrenal gland into the bloodstream as part of the fight-or-flight response. Norepinephrine is also present in the brain and is used as a neurotransmitter in normal brain processes.

Nucleus A cluster or group of nerve cells that is dedicated to performing its own special function(s). Nuclei are found in all parts of the brain except the cerebral cortex, where such groups are called cortical fields.

Nucleus accumbens A part of the brain reward system, located in the limbic system, that processes information related to motivation and reward. It is the key brain site where virtually all drugs of abuse act to reinforce drug taking.

Open-label study A study in which both doctor and patient know that patients are receiving an experimental drug and what that drug is.

Operant conditioning An unconscious form of learning in which a behavior is linked to a specific stimulus through a process of reinforcement.

Opiate receptors Receptors that recognize both opiates and endogenous opioids. When activated, they slow down or inhibit the activity of neurons on which they reside.

Opiates Any of the psychoactive drugs that originate from the opium poppy or that have a chemical structure like the drugs derived from opium. Such drugs include opium, codeine, and morphine (derived from the plant), and hydromorphone (Dilaudid), methadone, and meperidine (Demerol), which were first synthesized by chemists.

Opiate Receptors The opiate receptor and other brain receptors are proteins located on the surfaces of nerve cells, or neurons. The brain works through neurons communicating with each other by releasing signaling chemicals called neurotransmitters. These chemicals attach to receptors on nearby neurons the way a key fits a lock. Opiates bind spcifically to opiate receptors.

Opioid Any chemical that has opiate-like effects; commonly used to refer to neurochemicals that activate opiate receptors (see Opiate Receptors).

Opiophobia A health care provider's unfounded fear that patients will become physically dependent upon or addicted to opioids even when using them appropriately; can lead to the underprescribing of opioids for pain management.

Organic solvents One class of inhalants that includes substances such as gasoline, paint thinner, and glue. Organic solvents are neurotoxic because they dissolve fatty substances, including the axon's myeline sheath.

Outpatient treatment Nonresidential treatment for drug addiction. Patients live at home, often work, and come to a clinic for treatment.

Overdose The condition that results when too much of a drug is taken, making a person sick or unconscious and sometimes resulting in death.

Periaqueductal gray matter A set of nuclei deep within the brain stem that are involved with visceral functions. It also plays a role in the development of physical dependence on opiates.

Pharmacodynamics The study of the mechanisms of actions of a drug, the relationship between how much drug is in the body and its effects.

Pharmacokinetics The study of how the body absorbs drugs, how they are distributed throughout the body, and how the body gets rid of drugs.

Phencyclidine See PCP.

Physical dependence Changes that the brain and body undergo as they adapt to the continued presence of high doses of drugs. Because of these changes, the brain and body eventually come to require the presence of the drug to work properly.

Placebo An inactive substance.

Plasticity The capacity of the brain to change its structure and function within certain limits. Plasticity underlies brain functions such as learning and allows the brain to generate normal, healthy responses to long-lasting environmental changes.

Polydrug abuse The abuse of two or more drugs at the same time, such as CNS depressant abuse accompanied by abuse of alcohol.

Positive reinforcement Something that increases the likelihood that the behavior that elicited it will be repeated. Positive reinforcement is rewarding, and we typically perceive it as pleasure.

Positron emission tomography (PET) A technique for measuring brain function in living human subjects by detecting the location and concentration of tiny amounts of radioactive chemicals.

PET scanner The machine that detects the radioactive chemicals used to measure brain functions.

Postsynaptic neuron A neuron that receives messages from neurons on the other sides of its synapses.

Prefrontal cortex The part of the cerebral cortex at the very front of the brain. It is involved with higher cognitive and emotional functions including short-term memory, learning, and setting priorities for future actions.

Prescription drug abuse The intentional misuse of a medication outside of the normally accepted standards of its use.

Prescription drug misuse Taking a medication in a manner other than that prescribed or for a different condition than that for which the medication is prescribed.

Presynaptic neuron A neuron that releases neurotransmitters into synapses to send messages to other neurons.

Prevention Stopping drug use before it starts, intervening to halt the progression of drug use once it has begun, changing environmental conditions that encourage addictive drug use.

Primary reinforcers Stimuli, such as food and water, which produce reward directly, with no learning about their significance or other intervening steps required. Most drugs of abuse are primary reinforcers.

Projection neurons Neurons (usually excitatory) that send their axons away from the local vicinity to communicate with other parts of the brain.

Proteins Large molecules made up of amino acid building blocks.

Psilocybin A natural hallucinogenic drug derived from a mushroom. It acts on the serotonin receptor.

Psychedelic drug Drugs that distort perception, thought, and feeling. This term is typically used to refer to drugs with actions like those of LSD.

Psychoactive drug A drug that changes the way the brain works.

Psychological dependence When drugs become so central to a user's life that the user believes he must use them.

Psychosocial therapy Therapy designed to help addicts by using a combination of individual psychotherapy and group (social) therapy approaches to rehabilitate or provide the interpersonal and intrapersonal skills needed to live without drugs.

Psychotherapeutics Drugs that have an effect on the function of the brain and that often are used to treat psychiatric disorders; can include opioids, CNS depressants, and stimulants.

Quaalude The trademark Quaalude for the addictive sedative and hypnotic agent methaqualone. Methaqualone was developed in the 1960s by William H. Rorer, Inc. By 1972, "luding out" -- taking methaqualone with wine -- was a popular college pastime. Excessive use leads to tolerance, dependence, and withdrawal symptoms similar to those of barbiturates. In the United States, the marketing of methaqualone pharmaceutical products stopped in 1984, and methaqualone was transferred to Schedule I of the CSA. Quaalude is an example of how a product name is carefully chosen for a positive public response. At that time, the company's best-known product was Maalox, a digestive aid that derived its name from its ingredients, "ma"gnesium and "al"uminum hydr"ox"ides. To enhance the product recognition of methaqualone, the company incorporated the "aa" of Maalox into the name Quaalude. The other elements of the name are presumed to be a contraction of the phrase "quiet interlude" -- a soothing, even poetic description of a drug with dangerously hypnotic and addictive effects.

Receptor A large molecule that recognizes specific chemicals (normally neurotransmitters, hormones, and similar endogenous substances) and transmits the message carried by the chemical into the cell on which the receptor resides.

Rehabilitate Helping a person recover from drug addiction. Rehabilitation teaches the addict new behaviors to live life without drugs.

Relapse In general, to fall back to a former condition. Here, resuming the use of a drug one has tried to stop using. Relapse is a common occurrence in many chronic disorders that require behavioral adjustments to treat effectively.

Respiratory center A small set of nuclei in the brain stem that regulate the speed and depth of breathing ultimately by controlling the muscles that move our chest and diaphragm.

Respiratory depression Depression of respiration (breathing) that results in the reduced availability of oxygen to vital organs.

Reuptake The process by which neurotransmitters are removed from the synapse by being "pumped" back into the axon terminals that first released them.

Reuptake pump The large molecule that actually transports neurotransmitter molecules back into the axon terminals that released them.

Reward The process that reinforces behavior. It is mediated at least in part by the release of dopamine into the nucleus accumbens. Human subjects report that reward is associated with feelings of pleasure.

Rock A small amount of crack cocaine in a solid form; free-base cocaine in solid form.

Route of administration The way a drug is put into the body. Eating, drinking, inhaling, injecting, snorting, smoking, and absorbing a drug through mucous membranes all are routes of administration used to consume drugs of abuse.

"Run" A binge of (more or less) uninterrupted consumption of a drug for several hours or days. This pattern of drug use is typically associated with stimulants, but is seen with alcohol as well.

Rush Intense feelings of euphoria a drug produces when it is first consumed. Drug users who inject or smoke drugs describe their rush as being sometimes as intense, or even more intense, than sexual orgasm.

Seconal A depressant drug of the barbiturate family that induces sleep.

Second messenger A molecule produced inside neurons as a step in the process of communication between cells. The second messenger lets other parts of the cell know that a specific receptor has been activated, thereby completing the message carried by the neurotransmitter that bound to the receptor. Some receptors (e.g., dopamine, opiate) use second messengers. Others (e.g., nicotine, GABA) do not.

Secondary reinforcers Formerly neutral stimuli that acquire the ability to produce reward through the learned association with a primary reinforcer. Money and praise are secondary reinforcers.

Sensitization An increased response to a drug caused by repeated administration. Sensitization is most commonly seen in some responses to stimulants.

Serotonin A neurotransmitter involved in many functions, including mood, appetite, and sensory perception.

Short-term effects The acute effects of a drug. The effects felt during and shortly after the time a person is under the influence of (intoxicated by) a drug.

Short-term memory Also called "working memory," short-term memory enables us to use information from our senses and from our memory and hold that information in our consciousness long enough to think about it.

"Skinner Box" A device that automatically released food in response to an animal manipulating a specific object (e.g., pressing a bar) to test "operant conditioning", named after the classic experiments of psychologist B.F. Skinner who trained rats and pigeons to press a lever in order to obtain a food reward.

Skin popping Injecting a drug under the skin.

Somatosensory cortex A brain region that processes information coming from the muscles, joints, and skin.

Stimulants A class of drugs that elevates mood, increases feelings of well-being, and increases energy and alertness. These drugs also produce euphoria and are powerfully rewarding. Stimulants include cocaine, methamphetamine, and methylphenidate (Ritalin).

Stimulus Any object or action that penetrates awareness or excites an animal to respond.

Stroke The blockade or rupture of a blood vessel in the brain. This prevents oxygen from reaching neurons and may result in their death.

Synapse The site where neurons communicate with each other. A synapse is a small gap that physically separates neurons. Axon terminals of a neuron sending a message (the presynaptic neuron) release neurotransmitters into the synapse. The neurotransmitters diffuse to the other side (the postsynaptic side) where they bind to receptors on the postsynaptic neurons, thereby relaying the message.

Synaptic transmission See Neurotransmission.

Synthesize To make a chemical from constitutional parts. Exact copies of drugs found in nature or created in the laboratory are synthesized in laboratories from simpler chemicals. Many substances are also synthesized in cells (e.g., large proteins such as receptors, or smaller ones such as neurotransmitters).

Tolerance A physiological change resulting from repeated drug use that requires the user to consume increasing amounts of the drug to get the same effect a smaller dose used to give; often leads to physical dependence.

Toxic Poisonous; temporary or permanent drug effects that are detrimental to the functioning of an organ or group of organs

Tranquilizers Depressant drugs that relieve anxiety.

Transdermal absorption Absorption through the skin.

Transporter A large molecule that straddles the cell membrane of the axon terminals of neurons. It removes neurotransmitter molecules from the synapse by ferrying them back into the axon terminal that released them.

Triggers Formerly neutral stimuli that have attained the ability to elicit drug craving following repeated pairing with drug use; also called cues.

Valium A depressant drug of the benzodiazepine family that relieves anxiety.

Ventral tegmental area (VTA) The group of dopamine-containing neurons that make up a key part of the brain reward system. The key targets of these neurons include the nucleus accumbens and the prefrontal cortex.

Wernicke, Carl The scientist who discovered the area of the cerebral cortex that allows us to understand language. People with damage in this area of the cortex are unable to understand spoken or written words.

Wernicke-Korsakoff's syndrome A brain disorder characterized by the loss of the brain's ability to store memories.

Withdrawal The period during which a person stops using a drug to which they are addicted; see Withdrawal Symptoms.

Withdrawal Symptoms Physical (body and brain ) and/or psychological (mental/emotional) symptoms that occur after stopping drug use in a person who is physically or emtionally dependent on that drug. Withdrawal symptoms can be mild, moderate, severe and even life threatening depending on the specific case and circumstances.